Abstract: A safety disconnect system for an installation comprising machines which are designed to interact, has a machine disconnect level in which a dedicated disconnect circuit is allocated to each machine, an area disconnect level, in which disconnect areas which comprise groups of associated machines can be disconnected, and a system disconnect level which is allocated to all the machines of the installation. The disconnect circuits in each case have an electrically operable switching element which is connected via safety circuits to a main box for the central control of the safety disconnect system and, through this box, to a power supply. The safety circuits have operable tripping elements at the area disconnect level and at the system disconnect level, are constructed as latching circuits and are passed through the main box in which they can optionally be linked to one another by means of a switching matrix such that groups of associated machines are disconnected if one of the tripping elements is operated.